相关论文: The Mass-Loss History of the Red Hypergiant VY CMa

High spatial and spectral resolution spectroscopy of the OH/IR supergiant VY CMa and its circumstellar ejecta reveals evidence for high mass loss events from localized regions on the star occurring over the past 1000 years. The reflected…

The red hypergiant VY CMa and the more typical red supergiant Betelgeuse provide clear observational evidence for discrete, directed gaseous outflows in their optical and infrared imaging, spectra, and light curves. In the very luminous VY…

Images of the complex circumstellar nebula associated with the famous red supergiant VY CMa show evidence for multiple and asymmetric mass loss events over the past 1000 yrs. Doppler velocities of the arcs and knots in the ejecta showed…

Red supergiant stars (RSGs, Minit = 10-40Msun) are known to eject large amounts of material, as much as half of their initial mass during this evolutionary phase. However, the processes powering the mass ejection in low- and…

The red hypergiant VY CMa is famous for its very visible record of high mass loss events. Recent CO observations with ALMA revealed three previously unknown large scale outflows (Paper I). In this paper we use the CO maps to investigate the…

HST/STIS spectra of the small clumps and filaments closest to the central star in VY CMa reveal that the very strong K I emission and TiO and VO molecular emission, long thought to form in a dusty circumstellar shell, actually originate in…

The red hypergiant VY CMa is remarkable for its very visible record of high mass loss events observed over the range of wavelengths from the optical and infrared to the submillimeter region with ALMA. The SW Clump or SW knots are unique in…

The complex circumstellar ejecta of highly evolved, cool hypergiants are indicative of multiple, asymmetric mass loss events. To explore whether such episodic, non-isotropic mass loss may be driven by surface magnetic activity, we have…

With a luminosity > 10^5 Lsun and a mass-loss rate of about 2.10-4 Msun/yr, the red supergiant VY CMa truly is a spectacular object. Because of its extreme evolutionary state, it could explode as supernova any time. Studying its…

We present new observations of the red supergiant VY CMa at 1.25 micron, 1.65 micron, 2.26 micron, 3.08 micron and 4.8 micron. Two complementary observational techniques were utilized: non-redundant aperture masking on the 10-m Keck-I…

We present high-resolution 4.6micron CO spectra of the circumstellar environments of two RSGs that are potential SN progenitors: Betelgeuse and VY CMa. Around Betelgeuse, 12CO emission within 3arcsec follows a mildly clumpy but otherwise…

We present mid- and far- IR imaging of four famous hypergiant stars: the red supergiants $\mu$ Cep and VY CMa, and the warm hypergiants IRC +10420 and $\rho$ Cas. Our 11 to 37 $\mu$m SOFIA/FORCAST imaging probes cool dust not detected in…

The star VY CMa is a late-type M supergiant with many peculiarities, mostly related to the intense circumstellar environment due to the star's high mass-loss rate. Claims have been made that would suggest this star is considerably more…

Massive stars live short lives, losing large amounts of mass through their stellar wind. Their mass is a key factor determining how and when they explode as supernovae, enriching the interstellar medium with heavy elements and dust. During…

Context: Mass loss plays a dominant role in the evolution of low mass stars while they are on the Asymptotic Giant Branch (AGB). The gas and dust ejected during this phase are a major source in the mass budget of the interstellar medium.…

Long-slit echelle spectra reveal bright extended emission from the K I lambda7699 resonance line in the reflection nebula surrounding the extreme red supergiant VY Canis Majoris. The central star has long been known for its unusually-bright…

We report astrometric results of phase-referencing VLBI observations of 43 GHz SiO maser emission toward the red hypergiant VY Canis Majoris (\vycma) using the Very Long Baseline Array (VLBA). We measured a trigonometric parallax of 0.83…

The envelope of the red supergiant VY CMa has long been considered an extreme example of episodic mass loss that is possibly taking place in other cool and massive evolved stars. Recent submm observations of the envelope revealed massive…

The processes leading to dust formation and the subsequent role it plays in driving mass loss in cool evolved stars is an area of intense study. Here we present high resolution ALMA Science Verification data of the continuum emission around…

We have used the VLA to detect emission from the supergiant VY CMa at radio wavelengths and have constructed 3000-4500 K isothermal outer atmospheres constrained by the data. These models produce a radio photosphere at 1.5-2 R_ast. An…